/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */
package org.apache.iotdb.db.sync.transport.client;

import org.apache.iotdb.common.rpc.thrift.TSStatus;
import org.apache.iotdb.commons.exception.sync.SyncConnectionException;
import org.apache.iotdb.commons.exception.sync.SyncHandshakeException;
import org.apache.iotdb.commons.sync.utils.SyncConstant;
import org.apache.iotdb.db.conf.IoTDBConfig;
import org.apache.iotdb.db.conf.IoTDBDescriptor;
import org.apache.iotdb.db.sync.pipedata.PipeData;
import org.apache.iotdb.db.sync.pipedata.TsFilePipeData;
import org.apache.iotdb.db.sync.sender.pipe.Pipe;
import org.apache.iotdb.rpc.RpcTransportFactory;
import org.apache.iotdb.rpc.TConfigurationConst;
import org.apache.iotdb.rpc.TSStatusCode;
import org.apache.iotdb.service.rpc.thrift.IClientRPCService;
import org.apache.iotdb.service.rpc.thrift.TSyncIdentityInfo;
import org.apache.iotdb.service.rpc.thrift.TSyncTransportMetaInfo;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.protocol.TCompactProtocol;
import org.apache.thrift.protocol.TProtocol;
import org.apache.thrift.transport.TSocket;
import org.apache.thrift.transport.TTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.nio.ByteBuffer;

import static org.apache.iotdb.commons.sync.utils.SyncConstant.DATA_CHUNK_SIZE;

public class IoTDBSyncClient implements ISyncClient {

    private static final Logger logger = LoggerFactory.getLogger(IoTDBSyncClient.class);

    private static final IoTDBConfig config = IoTDBDescriptor.getInstance().getConfig();

    private static final int TRANSFER_BUFFER_SIZE_IN_BYTES = 1 * 1024 * 1024;

    private TTransport transport = null;
    private volatile IClientRPCService.Client serviceClient = null;

    /* remote IP address*/
    private final String ipAddress;
    /* remote port */
    private final int port;
    /* database name that client belongs to*/
    private final String databaseName;

    private final Pipe pipe;

    /**
     * Create IoTDBSyncClient only for data transfer
     *
     * @param pipe          sync task
     * @param remoteAddress remote ip address
     * @param port          remote port
     * @param databaseName  database name that client belongs to
     */
    public IoTDBSyncClient(Pipe pipe, String remoteAddress, int port, String databaseName) {
        RpcTransportFactory.setThriftMaxFrameSize(config.getThriftMaxFrameSize());
        this.pipe = pipe;
        this.ipAddress = remoteAddress;
        this.port = port;
        this.databaseName = databaseName;
    }

    /**
     * Create IoTDBSyncClient only for heartbeat
     *
     * @param pipe          sync task
     * @param remoteAddress remote ip address
     * @param port          remote port
     */
    public IoTDBSyncClient(Pipe pipe, String remoteAddress, int port) {
        this(pipe, remoteAddress, port, "");
    }

    /**
     * Create thrift connection to receiver. Check IoTDB version to make sure compatibility
     *
     * @return true if S; false if failed to check IoTDB version.
     * @throws SyncConnectionException cannot create connection to receiver
     * @throws SyncHandshakeException  cannot handshake with receiver
     */
    @Override
    public synchronized void handshake() throws SyncConnectionException {
        if (transport != null && transport.isOpen()) {
            transport.close();
        }

        try {
            transport =
                    RpcTransportFactory.INSTANCE.getTransport(
                            new TSocket(
                                    TConfigurationConst.defaultTConfiguration,
                                    ipAddress,
                                    port,
                                    SyncConstant.SOCKET_TIMEOUT_MILLISECONDS,
                                    SyncConstant.CONNECT_TIMEOUT_MILLISECONDS));
            TProtocol protocol;
            if (config.isRpcThriftCompressionEnable()) {
                protocol = new TCompactProtocol(transport);
            } else {
                protocol = new TBinaryProtocol(transport);
            }
            serviceClient = new IClientRPCService.Client(protocol);

            // Underlay socket open.
            if (!transport.isOpen()) {
                transport.open();
            }

            TSyncIdentityInfo identityInfo =
                    new TSyncIdentityInfo(
                            pipe.getName(), pipe.getCreateTime(), config.getIoTDBMajorVersion(), databaseName);
            TSStatus status = serviceClient.handshake(identityInfo);
            if (status.code != TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
                throw new SyncHandshakeException(
                        String.format(
                                "the receiver rejected the synchronization task because %s", status.message));
            }
        } catch (TException e) {
            throw new SyncConnectionException(
                    String.format("cannot connect to the receiver because %s", e.getMessage()));
        }
    }

    /**
     * Send {@link PipeData} to receiver and load. If PipeData is TsFilePipeData, The TsFiles will be
     * transferred before the PipeData transfer.
     *
     * @return true if success; false if failed to send or load.
     * @throws SyncConnectionException cannot create connection to receiver
     */
    @Override
    public boolean send(PipeData pipeData) throws SyncConnectionException {
        if (pipeData instanceof TsFilePipeData) {
            try {
                for (File file : ((TsFilePipeData) pipeData).getTsFiles(true)) {
                    if (!transportSingleFilePieceByPiece(file)) {
                        return false;
                    }
                }
            } catch (IOException e) {
                logger.error(String.format("Get TsFiles error, because %s.", e), e);
                return false;
            }
        }
        try {
            return transportPipeData(pipeData);
        } catch (IOException e) {
            logger.error(String.format("Transport PipeData error, because %s.", e), e);
            return false;
        }
    }

    /**
     * Transport file piece by piece.
     *
     * @return true if success; false if failed.
     * @throws SyncConnectionException Connection exception, wait for a while and try again
     * @throws IOException             Serialize error.
     */
    private boolean transportSingleFilePieceByPiece(File file)
            throws SyncConnectionException, IOException {
        // Cut the file into pieces to send
        long position = 0;
        long limit = getFileSizeLimit(file);

        // Try small piece to rebase the file position.
        byte[] buffer = new byte[TRANSFER_BUFFER_SIZE_IN_BYTES];
        int dataLength;
        try (RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r")) {
            while (position < limit) {
                // Normal piece.
                if (position != 0L && buffer.length != DATA_CHUNK_SIZE) {
                    buffer = new byte[DATA_CHUNK_SIZE];
                }
                dataLength =
                        randomAccessFile.read(buffer, 0, Math.min(buffer.length, (int) (limit - position)));
                if (dataLength == -1) {
                    break;
                }
                ByteBuffer buffToSend = ByteBuffer.wrap(buffer, 0, dataLength);
                TSyncTransportMetaInfo metaInfo = new TSyncTransportMetaInfo(file.getName(), position);

                TSStatus status = serviceClient.sendFile(metaInfo, buffToSend);

                if ((status.code == TSStatusCode.SUCCESS_STATUS.getStatusCode())) {
                    // Success
                    position += dataLength;
                } else if (status.code == TSStatusCode.SYNC_FILE_REDIRECTION_ERROR.getStatusCode()) {
                    position = Long.parseLong(status.message);
                } else if (status.code == TSStatusCode.SYNC_FILE_ERROR.getStatusCode()) {
                    logger.error(
                            "Receiver failed to receive data from {} because {}, abort.",
                            file.getAbsoluteFile(),
                            status.message);
                    return false;
                }
            }
        } catch (TException e) {
            logger.error("Cannot sync data with receiver. ", e);
            throw new SyncConnectionException(e);
        }
        return true;
    }

    private long getFileSizeLimit(File file) {
        File offset = new File(file.getPath() + SyncConstant.MODS_OFFSET_FILE_SUFFIX);
        if (offset.exists()) {
            try (BufferedReader br = new BufferedReader(new FileReader(offset))) {
                return Long.parseLong(br.readLine());
            } catch (IOException e) {
                logger.error(
                        String.format("Deserialize offset of file %s error, because %s.", file.getPath(), e));
            }
        }
        return file.length();
    }

    /**
     * Transport and load PipeData
     *
     * @return true if success; false if failed.
     * @throws SyncConnectionException Connection exception, wait for a while and try again
     * @throws IOException             Serialize error.
     */
    private boolean transportPipeData(PipeData pipeData) throws SyncConnectionException, IOException {
        try {
            byte[] buffer = pipeData.serialize();
            ByteBuffer buffToSend = ByteBuffer.wrap(buffer);
            TSStatus status = serviceClient.sendPipeData(buffToSend);
            if (status.code == TSStatusCode.SUCCESS_STATUS.getStatusCode()) {
                logger.info("Transport PipeData {} Successfully", pipeData);
            } else if (status.code == TSStatusCode.PIPESERVER_ERROR.getStatusCode()) {
                logger.error("Receiver failed to load PipeData {}, skip it.", pipeData);
                return false;
            }
        } catch (TException e) {
            throw new SyncConnectionException(e);
        }
        return true;
    }

    @Override
    public void close() {
        if (transport != null) {
            transport.close();
            transport = null;
        }
    }
}
